Pain is not just an internal experience, it is shared with others in a number of ways. Observers can see, evaluate and interpret peoples' painful experiences.
A very recent publication (Hadjistavropoulos et al., 2011) presented a detailed framework for understanding the numerous and complicated interactions between psychological, biological and social determinants of painful experiences. This is indeed very nice overview of published studies and research on the pain communication. However, we are still in the beginning of the way. Our knowledge about interpretation of pain signals in social interactions and the effect of observer's characteristics on these interpretations is incomplete and still further research is needed.
Based on this review article, we would like to have more comments on this topic.